Card cage racks or chassis are well known in industry for supporting a variety of electrical components. For example, many commercial buildings today have very complex communications and other electrical needs. In order to provide these commercial establishments with telephone and other communications service that is necessary today, many buildings have dedicated areas or closets for storing this type of equipment. These storage areas are rapidly becoming filled with a variety of electrical components. As a result, there is a need for a device for accommodating this equipment in an orderly, safe and accessible manner. Traditionally, the industry has used a variety of card cage racks to accommodate various modules that are used.
Modern electronic systems often employ a number of electronic circuit modules, typically printed wiring boards (PWBs) or printed circuit (PC) cards populated with electronic components and connectors, mounted in an electronic housing or rack. Typical racks often include a plurality of card slots for receiving circuit modules, with card edge guides to hold the cards in alignment, insertion/removal elements, a card connector, and a backplane for providing circuit interconnections. Circuit backplanes are often multilayer printed wiring boards designed for high speed interconnection of signals between different circuit components mounted on physically separated circuit modules in different slots. In most configurations, the circuit modules include electrical connectors affixed to the rear of the circuit module that are plug-action coupled to mating connectors on the backplane.
In some rack configurations, for example those employed in the cable television (CATV) and other telecommunications equipment industries, the circuit modules include discrete drop side signal connectors (electrical and/or optical) affixed to the circuit modules that couple to cables that carry signals to and from the equipment rack. In some of these configurations, the discrete signal connectors are mounted to the rear edge of the circuit modules and extend through openings in and the backplane and the housing rack so as to allow connection of the drop side signal cables. In other configurations, connectors are provided on the front edge of a circuit module to allow for signal insertion and extraction.
These card cage racks are typically in the form of a box like container having a base member and a top member that are provided with a plurality of rails for retaining cards or modules that are to be held by the rack. The base member and the top member are joined by a pair of opposing side walls and a rear wall. Positioned within the card cage structure are card rails or guides that extend generally between the front and rear cross members. These card guides have grooves that are opposing between the lower and upper card guide rails, for receiving the edges of the circuit boards. The card guides are also laterally spaced from each other, to provide space between the electrical and electronic components secured to the circuit boards. At the end of the known circuit boards, there is an electrical connection that interconnects with an electrical connection on the rear panel, known as the back plane electrical connector. The front wall area is typically left open to install the cards. Once the cards are installed there may be a front cover that is placed over any remaining empty slots in the rack to protect them. The cover is usually connected to flanges that extend from the side walls of the rack to hold the cover.
One of the problems with racks of the prior art is their lack of interchangeability and the absence of modularity. Prior art racks come in different sizes and configurations and as a result, the customer or the supplier was required to keep on hand a number of different sizes and configurations. This requires a significant investment. In addition, the prior art racks because of their complexity were relatively expensive.